10 Telescopes That Changed Our View of the Universe [Slide Show]

Historic telescopes through the ages, from Galileo to the 21st century

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SPITZER SPACE TELESCOPE:

The last of NASA's Great Observatories, Spitzer is a space-based infrared telescope. As it does with x-rays, Earth's atmosphere absorbs a lot of infrared radiation, so a telescope in space affords astronomers a much clearer view of the universe.....[
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SPITZER SPACE TELESCOPE:

The last of NASA's Great Observatories, Spitzer is a space-based infrared telescope. As it does with x-rays, Earth's atmosphere absorbs a lot of infrared radiation, so a telescope in space affords astronomers a much clearer view of the universe. Spitzer was launched in 2003 and has significantly advanced our knowledge of star-forming regions, young stars and other solar systems.

CHANDRA X-RAY OBSERVATORY:

Another of NASA's Great Observatories, Chandra was launched via the space shuttle in 1999. It primarily observes soft x-rays. The Earth's atmosphere absorbs most x-rays, so a space-based telescope is essential to gain good observations in that part of the spectrum.....[
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CHANDRA X-RAY OBSERVATORY:

Another of NASA's Great Observatories, Chandra was launched via the space shuttle in 1999. It primarily observes soft x-rays. The Earth's atmosphere absorbs most x-rays, so a space-based telescope is essential to gain good observations in that part of the spectrum. In its decade of existence Chandra has already produced many firsts, including the first observation of x-rays as matter streams into Sagittarius A*, the supermassive black hole at the center of the Milky Way Galaxy.

W. M. KECK OBSERVATORY

The twin giant Keck telescopes are situated at 4,150 meters atop Mauna Kea, one of the world's best astronomical observing sites, and each has a primary mirror that is 10 meters across. The first telescope, Keck 1, began observations in 1993, followed by Keck 2 in 1996.....[
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W. M. KECK OBSERVATORY

The twin giant Keck telescopes are situated at 4,150 meters atop Mauna Kea, one of the world's best astronomical observing sites, and each has a primary mirror that is 10 meters across. The first telescope, Keck 1, began observations in 1993, followed by Keck 2 in 1996. Taken together, they are the world's largest optical observatory. Both have adaptive optics that allow astronomers to cancel out some of the "fog" of Earth's atmosphere. Keck 1 has an infrared camera so sensitive, it is said that it could detect the flame of a single candle placed on the moon. The Keck Observatory has been invaluable in detecting extrasolar planets, worlds around other stars that were long postulated but only detected in the last dozen years or so.

HUBBLE SPACE TELESCOPE:

The first of NASA's Great Observatories, the Hubble Space Telescope was carried into orbit in 1990 by the space shuttle. Hubble was originally designed to observe in the visible and ultraviolet parts of the spectrum, but a 1997 mission added an infrared observing capability.....[
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HUBBLE SPACE TELESCOPE:

The first of NASA's Great Observatories, the Hubble Space Telescope was carried into orbit in 1990 by the space shuttle. Hubble was originally designed to observe in the visible and ultraviolet parts of the spectrum, but a 1997 mission added an infrared observing capability. Because it orbits hundreds of miles above Earth, Hubble does not suffer from the atmospheric distortions encountered by Earthbound observatories and has been our clearest eye into space, vastly expanding our knowledge of the cosmos and its origins.

PALOMAR OBSERVATORY AND THE 200-INCH HALE TELESCOPE:

The 200-inch Hale telescope on Mount Palomar, about three hours' drive south of Los Angeles, was also the brainchild of George Ellery Hale. The astronomer, however, did not live to see the completion of the scope, which took 20 years to build.....[
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PALOMAR OBSERVATORY AND THE 200-INCH HALE TELESCOPE:

The 200-inch Hale telescope on Mount Palomar, about three hours' drive south of Los Angeles, was also the brainchild of George Ellery Hale. The astronomer, however, did not live to see the completion of the scope, which took 20 years to build. Named in his honor, it saw its first light in 1949. Until the 10-meter Keck 1 was built in 1993, the Hale telescope had the best resolving power in the world. The telescope was central to solving the puzzle of quasars.

KARL JANSKY'S RADIO ANTENNA

Karl Jansky, a physicist who worked at AT&T Bell Laboratories in Holmdel, N.J., built a radio antenna that was roughly 100 feet long and 20 feet high to monitor short-wavelength radio waves. Jansky wanted to see if they interfered with transatlantic telephone calls.....[
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KARL JANSKY'S RADIO ANTENNA

Karl Jansky, a physicist who worked at AT&T Bell Laboratories in Holmdel, N.J., built a radio antenna that was roughly 100 feet long and 20 feet high to monitor short-wavelength radio waves. Jansky wanted to see if they interfered with transatlantic telephone calls. After months of observations, he noticed that one unidentified yet persistent source of noise was coming from the direction of the constellation Sagittarius. Jansky realized that the radio waves were coming from the center of the Milky Way. It was 1933, and this was the birth of radio astronomy.

MOUNT WILSON OBSERVATORY AND THE 100-INCH HOOKER TELESCOPE:

In the 19th and early 20th centuries, advances in glassmaking, along with lens grinding and polishing, led to the building of larger and larger telescopes, often on mountaintops that were suitable for astronomical observations because of thinner air and darker skies.....[
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MOUNT WILSON OBSERVATORY AND THE 100-INCH HOOKER TELESCOPE:

In the 19th and early 20th centuries, advances in glassmaking, along with lens grinding and polishing, led to the building of larger and larger telescopes, often on mountaintops that were suitable for astronomical observations because of thinner air and darker skies. In the U.S., observatories such as Lick in San Jose, Calif., and Yerkes in Williams Bay, Wisc., were among the first to show the uses of big observatories. American astronomer George Ellery Hale built a number of great telescopes, including the 100-inch Hooker telescope on Mount Wilson outside Los Angeles. The telescope, which started observations in 1917, was used by astronomer Edwin Hubble to gather data indicating an expanding universe, a discovery that shattered the steady-state cosmological orthodoxy of the time.

HERSCHEL'S 40-FOOT TELESCOPE:

William Herschel, who discovered Uranus, built a reflecting telescope in Slough, England, that was 40 feet in length, the largest of its day. It was constructed from 1785 to 1789 at a cost of 4,000 pounds, which was paid by King George III.....[
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HERSCHEL'S 40-FOOT TELESCOPE:

William Herschel, who discovered Uranus, built a reflecting telescope in Slough, England, that was 40 feet in length, the largest of its day. It was constructed from 1785 to 1789 at a cost of 4,000 pounds, which was paid by King George III. It remained the largest telescope in the world for 50 years. On August 28, 1789, the first night of its operation, Herschel pointed it at Saturn and discovered one of its moons. He would go on to discover another of Saturnian satellite as well as two of Uranus's moons.

NEWTON'S TELESCOPE:

The British mathematician and physicist Isaac Newton built a telescope in 1670 that, unlike Galileo's device, used a mirror to gather and focus the incoming light. Such telescopes are called reflectors, and they offer major advantages over refractors, which use two lenses and suffer from optical distortion effects.....[
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NEWTON'S TELESCOPE:

The British mathematician and physicist Isaac Newton built a telescope in 1670 that, unlike Galileo's device, used a mirror to gather and focus the incoming light. Such telescopes are called reflectors, and they offer major advantages over refractors, which use two lenses and suffer from optical distortion effects. Reflector telescopes can also be made much, much larger than refractors. All the giant telescopes today are reflectors, and Newton's design paved the way for their development.

GALILEO'S TELESCOPE:

Galileo's instrument was a simple affair, a refractor telescope that had two lenses at the ends of two tubes, one of which slid into the other. Using it, he first observed the moon in the fall of 1609, then the moons of Jupiter, and sunspots.....[
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GALILEO'S TELESCOPE:

Galileo's instrument was a simple affair, a refractor telescope that had two lenses at the ends of two tubes, one of which slid into the other. Using it, he first observed the moon in the fall of 1609, then the moons of Jupiter, and sunspots. He also resolved faint nebular patches into stars. By March 1610, he had published Sidereus Nuncius (Starry Messenger), the landmark treatise that documented his observations and his explanations for them. Galileo postulated that there are mountains and plains on the moon, noted that he could see 10 times as many stars through his telescope as with the naked eye, and he saw the moons of Jupiter and deduced that they orbit the planet.